Chronic headache attributed to bacterial meningitis or meningoencephalitis

Diagnostic criteria:
  1. Headache fulfilling criteria for 9.1.1 Headache attributed to bacterial meningitis or meningoencephalitis, and criterion C below
  2. Bacterial meningitis or meningoencephalitis remains active1 or has resolved within the last 3 months
  3. Headache has been present for >3 months.

Demonstrated by MRI focal or multifocal contrast enhancement and/or persistence of CSF pleocytosis with or without evidence of blood brain barrier damage.